Photodiodes are commercially important for a wide range of applications. For example, a linear array of photodiodes may be used as wavelength monitors for wave length division multiplexing communication systems, spectroscopy and machine vision applications. Further, a two-dimensional array of photodiodes may be used in many applications ranging from surveillance to industrial process control. In many of the above applications, it may be preferable to use photodiodes on a smaller scale. However, simply reducing the size of photodiodes may bring serious repercussions, such as degradation of its light conversion efficiency.